The present invention relates generally to pneumatic manifolds and more specifically to pneumatic manifolds for rail vehicle brakes.
Manifolds for rail vehicle brakes include a plurality of faces having ports for connection to pneumatic devices, sources of pneumatic fluid and pneumatic circuits connected to the faces. In some cases, pneumatic devices are mounted on the face and in other cases, the pneumatic devices, sources of pneumatic fluid and pneumatic circuits are connected to the device by hoses or other couplings. The manifold is mounted to the rail vehicle. The rail vehicle may include locomotives or cars including freight, passenger and mass transit.
One example of a prior art manifold, used for example in a freight locomotive known as CCB from New York Air Brake Corporation, is illustrated in FIGS. 1-3 of U.S. Pat. No. 5,803,124. The manifold includes two plates having the interior faces machined to provide passages and chambers and the exterior faces machined to have bores for connecting the passages and chambers to ports on the exterior faces. The passages are generally shallower than the chambers. Adhesives are applied to the interior faces to bond the two plates together. The adhesives sometimes would extend into the shallow passages and block them. These manifolds had to be scrapped. Also, circuitous paths had to be selected for the connection of the ports on either a common face or the opposite exterior faces. This limited the placement of the ports on the exterior faces of the manifold. This is particularly detrimental where the pneumatic devices are mounted on one of the faces instead of just mere connection to external or non-mounted pneumatic device.
For the prior art structure of FIGS. 1-3 of U.S. Pat. No. 5,803,124, the two core plates, for example, are ¾ of an inch thick. This allowed a chamber depth of ½ inch into each plate for a combined depth of one inch chambers. If a bypass was needed because of the layout, a ¼ inch thick cover plate would be provided as a bypass plate on one of the exterior faces.
The prior art manifold according to FIGS. 1-3 of U.S. Pat. No. 5,803,124 was an improvement over a previous prior art manifold illustrated in FIG. 4 of U.S. Pat. No. 5,803,124. This included a center core plate with a pair of cover plates. The core plate was machined to include the chambers and passages and the cover plates provided connection to external ports. The cover plates were substantially thinner than the core plate. Typically, the core plate was one inch thick and the cover plate was ½ inch thick. The one-inch thick core plate limited the depths of the chambers to ¾ of an inch.
FIGS. 5-7 of U.S. Pat. No. 5,803,124 illustrated a three plate manifold wherein the center plate formed the crossover separation between chambers and passages in the two outer plates. The center plate had a thickness in the range of 1/16 to ¼ of an inch and the cover plates were ¾ of an inch thick. This manifold structure removes the limitation of the positioning of the chambers and passages.
The present manifold is a modification of the three plate manifold to two plates with all the same advantages. The present manifold includes first and second plates secured together at an inner face of each plate. A plurality of chambers and passages are in the inner faces of the plates and at least one port on an outer face of each plate connected to one of the chambers and passages. A crossover element in the inner face of the first plate separates a chamber or passage in the first plate from a chamber or passage in the second plate in the area where the chambers or passages cross.
The crossover element has a face flush with the inner face of the first plate. The crossing chamber or passage in the first plate has a first width in the inner face of the first plate and the crossover element has a second width greater than the first width. The crossover element may be in a recess in the inner face of the first plate and the recess has a width greater than a width of the crossing chamber or passage in the first plate and a depth less that a depth of the crossing chamber or passage in the first plate.
The crossover element may be a third plate, a disk and/or a block with a bore extending along the length of the crossing chamber or passage. Also, the crossover element may be a portion of the first plate over the crossing chamber or passage of the first plate. A portion of the crossing chamber or passage of the first plate below the crossover element has a depth into the first plate greater than the depth of an adjacent portion of the chamber or passage. The end walls of the crossover element are tapered.
A first chamber or passage in the second plate lies between a second and third chamber or passage in the second plate. The crossing chamber or passage in the first plate extends over the first chamber or passage and is connected to the second and third chambers or passages.
A method of making a manifold for a rail vehicle includes forming first and second plates each with a plurality of chamber or passage segments as a recess in an inner face of the plates and at least one port on an outer face of each plate connected to one of the chambers and passages. A crossover element is formed in the inner face of the first plate with a crossing chamber or passage there below connecting adjacent chamber or passage segments in the first plate. The inner surfaces of the first and second plates are positioned adjacent each other with the crossover element over a chamber or passage of the second plate and secured.
The crossover element is formed to have a face flush with the inner surface of the first plate. The crossover element may be formed by positioning it in the crossing chamber or passage with a face extending above the inner face of the first plate. Alternatively, the crossover element with a crossing chamber or passage there below may be formed by forming the crossing chamber or passage in the first plate below the inner surface of the first plate wherein the inner surface forms the crossover element.
The method includes forming the chamber or passage segments as recesses in an inner face of the plates includes vertical milling. Forming the crossover element with a crossing chamber or passage there below includes milling at an angle to the vertical from each adjacent vertically milled chamber or passage segment. The milling at an angle includes moving the angled milling element horizontally in the adjacent chamber or passage segment so that the depth of the crossover passage from the inner surface is at least as deep as the depth of the adjacent chamber or passage segment.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description when considered in conjunction with the accompanying drawings.